Acute intermittent porphyria (AIP) is an autosomal dominant inherited disease, which is relatively prevalent in northern Norway with a total of around 90 patients. This provides us with a special opportunity to study AIP. AIP is caused by a mutation in the porphobilinogen deaminase, an enzyme in the haem synthesis. AIP presents symptoms, particularly among fertile women and older men. Typical symptoms are abdominal pain and dark red urine, nausea, vomiting, constipation, muscle weakness and nerve damage including paraesthesia and even paresis. This is known as symptomatic or manifest AIP (MAIP). Others do not display symptoms, so-called latent AIP (LAIP). AIP attacks may be triggered by a host of medicaments which affect the haem synthesis, infections, alcohol and stress. Treatments of manifestations include high sugar intake (4 sugar lumps/hour), alternatively administer glucose and Normosang (synthetic haem arginate) by intravenous injection and removing triggering factors. Diet, glucose intake, dental health and inflammatory parameters will be examined. This study can provide new knowledge about why only some people develop symptoms of AIP. Main hypothesis: There are differences in the diet, iron status, inflammation and glucose metabolism of the MAIP group vs. the LAIP group and the control group.